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Wolfgang's user avatar
Wolfgang's user avatar
Wolfgang
  • Member for 12 years, 2 months
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38 votes

Collection of equivalent forms of Riemann Hypothesis

11 votes

Are there irreducible polynomials with all zeros on two concentric circles?

10 votes

Examples of unexpected mathematical images

8 votes

Examples of great mathematical writing

8 votes

The sequence $a_{n+1}=\left\lceil \frac{-1+\sqrt{5}}{2}a_{n}-a_{n-1} \right\rceil$ is periodic

8 votes
Accepted

Regular tournaments

8 votes

Examples of notably long or difficult proofs that only improve upon existing results by a small amount

7 votes
Accepted

A generalization of Erdős–Mordell inequality

7 votes
Accepted

Almost Hadamard matrices

7 votes

Can I build infinitely many polytopes from only finitely many prescribed facets?

7 votes

Number of turning points on a nondecreasing $n^2 \times n^2$ matrix

7 votes
Accepted

Number of polynomial terms for certain degree and certain number of variables

7 votes

Densest Graphs with Unique Perfect Matching

5 votes

Why does this sequence converges to $\pi$?

5 votes

Examples of unexpected mathematical images

5 votes

Two questions from combinatorics on words

5 votes

A special type of generating function for Fibonacci

5 votes

Minimal polynomial of cos(π/n)

5 votes

Spectrum of orthogonality graph (2)

5 votes
Accepted

dyadically recursive matrices: Part I

4 votes

Collection of equivalent forms of Riemann Hypothesis

4 votes

Pairwise disjoint subsets of $\mathbb{N}$ with positive upper density

4 votes

Eigenvalues and eigenvectors of the matrix with entries $\dbinom{n+1}{2j-i}$ for $i, j = 1, 2, \ldots, n$

4 votes

Examples of eventual counterexamples

4 votes

The discriminant of the Okada algebra

4 votes

Find the tight upper bound of $\sum_{i=1}^n \frac{i}{i+x_i}$, where the $x_i$'s are distinct in $\{1,2,...,n\}$

4 votes

Examples of unexpected mathematical images

4 votes
Accepted

Graphs with many edges avoided by Hamiltonian cycles

4 votes

S-matrix conjecture: status?

4 votes

Can a block matrix with at least 3 zero blocks of different size on the diagonal and 1's everywhere else have only integer eigenvalues?